from Wikipedia, the free encyclopedia
Central tubular frame of a Lotus Elan as "rolling chassis"
Box frame
Lower part of a self-supporting body from VW

The load-bearing parts of vehicles are called chassis , frame , chassis or underframe . Load-bearing parts have the function of supporting the drive , the body and the payload and stabilizing them against external forces. In vehicles with a self-supporting body , the body is the load-bearing element.

The wheel suspensions , all essential drive elements such as gearbox and engine , if necessary the body or transport goods container and trailer hitches are attached to the chassis . Chassis with built-in running gear and drive train can also be roadworthy without a body (“rolling chassis”).


  • Ladder frame : two longitudinal members made of open profiles connected with crossbars (widespread until the 1950s, today typical for trucks ). The ladder frame has the advantage that the total vehicle length, the wheelbase and the rear overhang can be varied with little effort. Attachments such as tanks can be attached to different parts of the frame.
  • Box frame: like ladder frame, but made of closed profiles (tubes), more torsion-resistant than ladder frames, suitable for all-steel bodies.
  • Lattice frame : three - dimensional framework (bars only subjected to tension and compression) usually made of tubes (motorcycles, sports cars - mostly from small series production).
  • Central tube frame : a round tube or a box made of sheet metal in the longitudinal axis ( Tatra , VW Beetle , VW Type 3 , Lotus Elan , Steyr-Puch Haflinger )
  • Platform frame: a base plate reinforced with closed profiles supports the chassis and body ( Renault 4 ).
  • " Space Frame ": Framework (parts also subject to bending and shear stress) made of tubes, which are reinforced by suitable connections, supporting sheets, but also glued-in window panes. ( Chrysler Airflow , AWS Shopper , Audi A8 )
  • Self-supporting , also known as a shell construction or monocoque : the structure currently used in car construction. Usually made of spot-welded sheet metal, is directly connected to the chassis and transfers all acting forces itself. Auxiliary frames (subframes) are occasionally used on the axles.

Not all types can be clearly assigned, since floor panels, for example, have a closed appearance, but can be dispensed with for the function of the chassis. The frame of the Citroën 2CV consists of two longitudinal members with cross members like a box frame, but is closed between the axles with metal sheets at the top and bottom like a central tubular frame.

Trucks with a body that extends far down to the ground are also built with center tube chassis.


Most frames are made from steel . In motorcycles also are frames made of aluminum alloys common. Composite materials are also used, especially in motorsport .

See also

Web links

Commons : Chassis  - collection of images, videos and audio files
Wiktionary: chassis  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. Michael Hilgers: Commercial vehicle technology: Chassis and axles , SpringerVieweg, Wiesbaden 2016, 66 pages, ISBN 978-3-658-12746-6 , e-book: ( doi : 10.1007 / 978-3-658-12747-3 )